Location

The location can be entered as x,y coordinates or as polar coordinates. Note that you will not be able to enter an angle until you have a non-zero radius because the program converts everything into x,y and then recomputes radius and angle.

The altitude box specifies the height of the main world disc. This is usually zero but if the point in question is near one of the topographical features and you don't want the program to produce an horizon with a 200 mile tall cliff right by your point, you should raise the altitude to reflect the slope of the feature you are near. With the infer Height option (defaults on), you cannot enter the height directly. Instead, MithlondSE infers the height from nearby topology objects. From the settings dialog, you can turn this off or change the slope that MithlondSE uses to objects when calculating height.

Date

Enter the day, month, and year for the day in question. If you want to render at a particular time,you must also enter the hour, minutes and seconds. If you are only doing day, month or year renders, you can leave hours/minutes/seconds as they are.

Note that for these controls MS Windows requires you to select the desired value so that it is highlighted. For instance, in the hours control, using the little up/down hours to change the hours to show a new value is not sufficient. You must also click on the value.

Rendering

The various render buttons show a single time, the sun throughout a day, or the daily arc of the sun hthroughout a month or year.

The view shows the full 360 degree horizon starting at 180 degrees in the left, 0 in the middle and -180 degrees in the right. It shows up to degrees above the horizon. If the sun is higher than that, it shows the sun at the top limit with (on day render only) the angle of the sun and an arrow below the sun.

There are options in the settings menu command to turn off the angle annotations, the hour marks on the day render, the black circle around the sun, etc.

You can also change the time between suns on daily render or daily arc and the number of days between arcs on a monthly or yearly render.

NOTE after changing the location, date, or through the settings menu command, the topology, you must hit a render button again to see the change. Setting options that are cosmetic occur immediately.

Note also that this view is a projection of a spherical portion onto a plane and is quite distorted as the angle increases.

You can resize the window. The sun is correctly scaled in the x and y dimensions. If your x and y dimensions are not of equal scale, the sun will appear flattened.

The color of the sun reflects the amount of thick atmosphere it is viewed through. The thick atmosphere is the atmosphere below the outer rim. This if you set altitude to the rim height or you choose a time and place where the sun is more overhead, it will appear whiter.

Topology Files

See the included topology files for syntax and examples.

The world disc directive sets the size of the world and the height of the world above the solar plane. The Rim defines the outer rim of mountains. Both must have a center of 0,0.

Ridges can be defined with a common height at both end points (flat) or with different heights. This is intended to be how all surface features are defined. Cones are provided mainly to make the ridges look proper when viewed end-on. The AutoCone directives can be used to automatically place cones at end points of all ridges.

The topology file also defines the radius of the sun’s orbit and the size of the sun (solar disc diameter).

WorldViews

WorldViews allow you to see what is happening on the entire world disc. You can look at a view for the current date or for the entire year.

Daily views require that you create a data set that records various data for every point on the disc on the current date. The yearly view is similar but computes a data set that gathers data for each point over the entire year. Naturally, the yearly view is a lot more compute intensive than the daily view.

The daily and yearly data sets can be saved. The daily set is typically less interesting since you will likely be frequently changing the date. But the yearly set is invariant and there is no need to regenerate it unless you want to change the settings or topology. The release .zip includes a yearly data set (YearlyData.ydt) that you can load rather than regenerating your own.

You must tell the program to create this data set since it can be time consuming. From the settings menu, you can change the time step used for the daily and yearly renders. Note that the default yearly step of 60 minutes is granular and can result in some artifacts on the world edge in some views. The time step and the world view resolution determine world view quality and the time necessary to create the data set.

Heat Maps

The heat map is the mapping of data to a range of colors. The default is a linear heat map but some views are better with a log heat map (usually the peak energy view). You can change from linear to log heat maps on the "View" menu of the world view.